tag.h revision 1.1.1.2 
1/*	$NetBSD: tag.h,v 1.1.1.2 2015/01/29 06:38:26 spz Exp $	*/
2/*	$NetBSD: tag.h,v 1.1.1.2 2015/01/29 06:38:26 spz Exp $	*/
3/*
4 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
5 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29#ifndef _EVENT2_TAG_H_
30#define _EVENT2_TAG_H_
31
32/** @file event2/tag.h
33
34  Helper functions for reading and writing tagged data onto buffers.
35
36 */
37
38#ifdef __cplusplus
39extern "C" {
40#endif
41
42#include <event2/event-config.h>
43#ifdef _EVENT_HAVE_SYS_TYPES_H
44#include <sys/types.h>
45#endif
46#ifdef _EVENT_HAVE_SYS_TIME_H
47#include <sys/time.h>
48#endif
49
50/* For int types. */
51#include <event2/util.h>
52
53struct evbuffer;
54
55/*
56 * Marshaling tagged data - We assume that all tags are inserted in their
57 * numeric order - so that unknown tags will always be higher than the
58 * known ones - and we can just ignore the end of an event buffer.
59 */
60
61void evtag_init(void);
62
63/**
64   Unmarshals the header and returns the length of the payload
65
66   @param evbuf the buffer from which to unmarshal data
67   @param ptag a pointer in which the tag id is being stored
68   @returns -1 on failure or the number of bytes in the remaining payload.
69*/
70int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
71
72void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
73    ev_uint32_t len);
74void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
75    struct evbuffer *data);
76
77/**
78  Encode an integer and store it in an evbuffer.
79
80  We encode integers by nybbles; the first nibble contains the number
81  of significant nibbles - 1;  this allows us to encode up to 64-bit
82  integers.  This function is byte-order independent.
83
84  @param evbuf evbuffer to store the encoded number
85  @param number a 32-bit integer
86 */
87void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
88void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
89
90void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
91    ev_uint32_t integer);
92void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
93    ev_uint64_t integer);
94
95void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
96    const char *string);
97
98void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
99    struct timeval *tv);
100
101int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
102    struct evbuffer *dst);
103int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
104int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
105int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
106int evtag_consume(struct evbuffer *evbuf);
107
108int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
109    ev_uint32_t *pinteger);
110int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
111    ev_uint64_t *pinteger);
112
113int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
114    void *data, size_t len);
115
116int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
117    char **pstring);
118
119int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
120    struct timeval *ptv);
121
122#ifdef __cplusplus
123}
124#endif
125
126#endif /* _EVENT2_TAG_H_ */
127